1. Field of the Invention
The present invention relates to a thermal transfer printer having a test printing function.
2. Description of the Prior Art
Thermal transfer printers have an advantage in printing on normal paper and have been recently popular. In a printer of this type, a thermal head having dot-like heating elements is moved in a printing direction (from left to right), and voltages are selectively applied to the heating elements. An ink on an ink ribbon is melted by heat from the heating elements and information is transferred onto normal paper.
Printing quality varies depending on the degree of smoothness of the surfaces of normal paper sheets (recording sheets) subjected to printing. For example, if the surface of a recording sheet is not so smooth, an ink is not satisfactorily transferred to the sheet, thus degrading printing quality. For this reason, in a conventional thermal transfer printer as described in "OKIMATE 20 Printer Hand book" (1984, OKIDATA), a printing density and a printing speed can be independently changed to perform printing, and test printing can be performed to adjust the printing conditions during test printing so as to match with paper quality. For example, if quality of a print is poor during test printing, a head voltage and hence the printing density is increased or a printing speed is decreased to improve printing quality. Upon completion of test printing, printing is initiated according to the adjusted printing density and speed.
Adjustment during test printing must be performed by changing combinations of printing density and speed and is time-consuming and cumbersome. Unless an operator is accustomed to adjustments to some extent, desired printing conditions cannot be set. When the operator is not accustomed to adjustments, he or she often may not even know that the printing density and speed are adjustable. As a result, the proper printing conditions are not often determined.